Hurwicz received a Guggenheim Fellowship for 1945–1946.[11] In 1946 he became a professor of economics at Iowa State College.[10] From January 1942 until June 1946, he was a researcher for the Cowles Commission. He worked full time for the Cowles Commission until October 1950 until January 1951, he was a visiting professor, teaching at classes that were taught before by Professor Koopman in the Department of Economics, and he was a very important professor there.[11] He was also a research professor of economics and statistics at the University of Illinois, a consultant to the RAND Corporation for the University of Chicago and a consultant to the U.S. government.[16] Hurwicz continued to be a consultant to the Cowles Commission until about 1961.[17]

In the University of Minnesota in 1961, Hurwicz became chairman of the Statistics Department, Regents Professor of Economics in 1969, and Curtis L. Carlson Regents Professor of Economics in 1989.[10] He taught subjects ranging from theory to welfare economics, public economics, rules for large companies and mathematical economics.[7] Although he retired from full time teaching in 1988,[9] Hurwicz taught graduate school as Professor Emeritus in the autumn of 2006.[9] In 2007 his ongoing research was described by the University of Minnesota as "comparison and analysis of systems and techniques of economic organization, welfare economics, game-theoretic implementation of social choice goals, and modeling economic institutions."[18] Professor Hurwiczs published works in these fields date back to 1944.[19] Professor Hurwicz is known internationally for his good work researching economic theory, specially with rules for big businesses and governments using mathematical economics. In the 1950s, he worked with Kenneth Arrow on non-linearprogramming.[4] Kenneth Arrow became the youngest person to receive the Nobel Economics prize in 1972.[20] Hurwicz helped Daniel McFadden,[21] who won a Nobel prize in 2000.[22]

Hurwiczs work was important to help show how large economic systems should be studied. Some of these systems are capitalism and socialism. Professor Hurwiczs ideas of how to share wealth are also very important.[23] The theory of incentive compatibility that Hurwicz developed changed the way many economists think about sharing in the future, explaining why centrally planned economies may fail and how rewards for certain people make a difference when making decisions.[21]

Hurwicz is part of teams who edit several journals. He co-edited and contributed to two collections for Cambridge University Press: Studies in Resource Allocation Processes (1978, with Kenneth Arrow) and Social Goals and Social Organization (1987, with David Schmeidler and Hugo Sonnenschein). His recent journals include "Economic Theory" (2003, with Thomas Marschak), "Review of Economic Design" (2001, with Stanley Reiter) and "Advances in Mathematical Economics" (2003, with Marcel K. Richter).[24] Hurwicz has taught works by Fisher-Schultz (1963), Richard T. Ely (1972), David Kinley (1989) and Colin Clark (1997).[source?]

Some important things have been given Professor Hurwiczs name such as the Hurwicz criterion, an idea that Professor Hurwicz had in 1950, and is thought of as very important for economics. The Hurwicz Criterion is also called "under uncertainty".[26][27][28] Hurwicz had the idea of putting Abraham Walds work together with work done by Pierre-Simon Laplace in 1812.[29] Hurwiczs Criterion tells people to think very carefully of what is good and what is bad before making decisions.[27] Different types of Hurwiczs Criterion have been thought of. Leonard Jimmie Savage made some changes to the first Hurwiczs criterion in 1954.[26] The four peoples work – Laplace, Wald, Hurwicz and Savage – that the Hurwicz Criterion has been based on was studied, corrected and used for over fifty years by many different people including John Milnor, G. L. S. Shackle,[26]Daniel Ellsberg,[30]R. Duncan Luce and Howard Raiffa, but some people say the work was started by Jacob Bernoulli.[31]

In October 2007, Hurwicz shared The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel with Eric Maskin of the Institute for Advanced Study and Roger Myerson of the University of Chicago "for having laid the foundations of mechanism design theory."[32] During a telephone interview, a member of the Nobel Foundation told Hurwicz and his wife that Hurwicz is the oldest person ever to win the Nobel Prize. Hurwicz said, "I hope that others who deserve it also got it." When he was asked what the most important part of mechanism design is, he said welfare economics.[33] The three Nobel prize winners used game theory work by mathematician John Forbes Nash, to discover the best way to reach a good outcome, without forgetting individual people.[34] Mechanism design has been used as a guide for talks and taxation, voting and elections,[5] to design auctions such as those for communications bandwidth,[21] elections and labor talks[34] and for pricing business stocks.[35]

Professor Hurwicz was not able to attend the Nobel Prize ceremony in Stockholm because of his age,[36][37] Hurwicz received the prize in Minneapolis. Accompanied by Evelyn, his wife for sixty years, and his family, he was the most important guest at a meeting in the University of Minnesota with the university president Robert Bruininks. After watching the Nobel Prize awards ceremony on television, Jonas Hafstrom, the Swedish ambassador to the United States, awarded the Economics Prize to Professor Hurwicz.[38]